golang测试TCP最大连接数

受限于本地端口数的分配,我想看看本地能起到多少个TCP client连接

本测试用例client和server都部署在同一台linux虚拟机上

查看进程打开的描述符数:102400(10万)

[root@bogon ~]# ulimit -a
core file size     (blocks, -c) 0
data seg size      (kbytes, -d) unlimited
scheduling priority       (-e) 0
file size        (blocks, -f) unlimited
pending signals         (-i) 15042
max locked memory    (kbytes, -l) 64
max memory size     (kbytes, -m) unlimited
open files           (-n) 102400
pipe size      (512 bytes, -p) 8
POSIX message queues   (bytes, -q) 819200
real-time priority       (-r) 0
stack size       (kbytes, -s) 8192
cpu time        (seconds, -t) unlimited
max user processes       (-u) 15042
virtual memory     (kbytes, -v) unlimited
file locks           (-x) unlimited

再看看测试代码,client端:

package main
import (
	_ "bytes"
	"fmt"
	"net"
	"net/url"
	_ "os"
	"strconv"
	"time"
)
var (
	DefalutTimeout = 25 * time.Second
	MaxClient   = 70000
	clientNum   = 0
	msg_nums    = 0
)
func sockConn(daemon string, timeout time.Duration) (net.Conn, error) {
	daemonURL, err := url.Parse(daemon)
	//fmt.Printf("daemon url %v %v \n", daemonURL, daemonURL.Scheme)
	if err != nil {
		return nil, fmt.Errorf("could not parse url %q: %v", daemon, err)
	}
	var c net.Conn
	switch daemonURL.Scheme {
	case "unix":
		return net.DialTimeout(daemonURL.Scheme, daemonURL.Path, timeout)
	case "tcp":
		return net.DialTimeout(daemonURL.Scheme, daemonURL.Host, timeout)
	default:
		return c, fmt.Errorf("unknown scheme %v (%s)", daemonURL.Scheme, daemon)
	}
}
func sendData(socket net.Conn, n int, msg_num_chan chan int) {
	buf := make([]byte, 10)
	for {
		_, err := socket.Write([]byte(strconv.Itoa(n)))
		if err != nil {
			fmt.Printf("Error reading:%s\n", err.Error())
			clientNum--
			return
		}
		//send reply
		_, err = socket.Read(buf)
		fmt.Printf("client %v\n", string(buf))
		if err != nil {
			fmt.Printf("Error send reply:%s\n", err.Error())
			clientNum--
			return
		}
		//time.Sleep(1 * time.Second)
		msg_num_chan <- 1
		buf = buf[0:]
	}
}
func connectServer(msg_num_chan chan int) {
	for i := 1; i <= MaxClient; i++ {
		socket, err := sockConn("tcp://127.0.0.1:8088", DefalutTimeout)
		if err != nil {
			fmt.Printf("connect error:%s\n", err)
		} else {
			clientNum++
			go sendData(socket, i, msg_num_chan)
		}
	}
}
func main() {
	msg_num_chan := make(chan int)
	connectServer(msg_num_chan)
	go func() {
		for msg_num := range msg_num_chan {
			msg_nums += msg_num
		}
	}()
	time.Sleep(10 * time.Second)
	fmt.Printf("rec msg %d \n", msg_nums)
}

Server端:

package main
import (
	"fmt"
	"net"
	"os"
	"time"
)
const (
	MAX_CONN_NUM = 100000
)
func EchoFunc(conn net.Conn) {
	defer conn.Close()
	buf := make([]byte, 10)
	for {
		_, err := conn.Read(buf)
		if err != nil {
			//println("Error reading:", err.Error())
			return
		}
		//fmt.Printf("server %s\n", string(buf))
		//send reply
		_, err = conn.Write(buf)
		if err != nil {
			//println("Error send reply:", err.Error())
			return
		}
	}
}
func main() {
	listener, err := net.Listen("tcp", "127.0.0.1:8088")
	if err != nil {
		fmt.Println("error listening:", err.Error())
		os.Exit(1)
	}
	defer listener.Close()
	fmt.Printf("running ...\n")
	var cur_conn_num int = 0
	conn_chan := make(chan net.Conn)
	ch_conn_change := make(chan int)
	go func() {
		for conn_change := range ch_conn_change {
			cur_conn_num += conn_change
		}
	}()
	go func() {
		for _ = range time.Tick(5e9) {
			fmt.Printf("cur conn num: %d\n", cur_conn_num)
		}
	}()
	for i := 0; i < MAX_CONN_NUM; i++ {
		go func() {
			for conn := range conn_chan {
				ch_conn_change <- 1
				EchoFunc(conn)
				ch_conn_change <- -1
			}
		}()
	}
	for {
		conn, err := listener.Accept()
		if err != nil {
			println("Error accept:", err.Error())
			return
		}
		conn_chan <- conn
	}
}

最后看看server端执行结果:

[root@bogon mpro]# go run server.go 
running ...
cur conn num: 0
cur conn num: 17452
cur conn num: 28233
cur conn num: 28233
cur conn num: 28233
^C^Cexit status 2

client端执行结果:

connect error:dial tcp 127.0.0.1:8088: cannot assign requested address
connect error:dial tcp 127.0.0.1:8088: cannot assign requested address
connect error:dial tcp 127.0.0.1:8088: cannot assign requested address
connect error:dial tcp 127.0.0.1:8088: cannot assign requested address
connect error:dial tcp 127.0.0.1:8088: cannot assign requested address
connect error:dial tcp 127.0.0.1:8088: cannot assign requested address

只能起到2万8个连接,最主要受限于端口数

本例只是测试client端的连接数,不是测试server的连接数

本文来自:开源中国博客

感谢作者:webyh

查看原文:golang测试TCP最大连接数

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